help with a potterton 40 wiring simple if you know

[gaza1987]

ok i have the above boiler has 1 spur just above the timer and an isolation switch above the boiler i went to move the switch today and now it wont work again im not sure if im wiring it up correctly or its broke it has been fine for 4 years now not a problem untill now please help me all i need is a wiring diagram

it is a gravity fed sytem with 1 motorised valve a tank stat 1 room stat and a timer

it turns on fine soon as you switch the heating on it goes stragit to red

 

[D_Hailsham]

If it's just an isolating switch, the wiring shouldn't be difficult.

Live (Brown), Neutral (Blue) and Earth (Green/Yellow) IN; Live, Neutral and earth OUT. The terminals should be marked.

 

[gaza1987]

thats what i thought but i have a 4 core cable there one cable has red black and bare the other cable has red black yellow and blue and earth

the boiler has blue red black and yellow there is a termail bloch which the yellow goes into which does not go into the swith i can not get the fan to come on which means no gas no flame no boiler it has to be the way these wires are any more help

 

[D_Hailsham]

thats what i thought but i have a 4 core cable there one cable has red black and bare

That's the old colour wires, so presumably the original wiring back to the spur.

Potterton made many boilers called the 40, what is the model name? It should be on the data plate. If not give the GC (Gas Council) number.

the boiler has blue red black and yellow there is a termail bloch which the yellow goes into which does not go into the switch

Don't understand. Are you saying that three of the wires connect isolator switch to the boiler; but the Yellow wire connects to the boiler at one end and to a terminal block at the other, which goes nowhere?


PS Don't you wish you had written down where each wire went before you disconnected.